#include <cstdio>

int main( )
{
    int n, f[ 2344 ], i;
    f[ 1 ] = 1;
    for ( i = 3; i <= 2343; i += 2 )
        f[ i ] = f[ i - 2 ] + i * i;
    while ( scanf("%d", &n) != EOF )
        printf("%d\n", f[ n ]);
    return 0;
}
